Device for fastening the operating die or ram in an extrusion press



Oct. 13, 1970 s. QUANTE 3,533,264

DEVICE FOR FASTENING THE OPERATING DIE 0R RAM IN AN EXTRUSION PRESS Filed May 3, 1967 3 Sheets-Sheei 2 lm/enf or:

SIEGFRIE D NTE Attorney Oct. 13, 1970 s. QUANTE 3,533,254

DEVICE FOR FASTENING THE OPERATING DIE OR RAM IN AN EXTRUSION PRESS Filed May 5. 1967 5 Sheets-Sheet 1 "Ill ml I Inventor: v s GFRIED NTE bv v I 4 Oct. 13, 1970 s. QUANTE 3,533,264

DEVICE FOR FASTENING THE OPERATING DIE OR RAM IN AN EXTRUSION PRESS 1 Filed May 5, 1967 5 Sheets-Sheet :s

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GFRIED ANTE by Attorney United States Patent 3,533,264 DEVICE FOR FASTENING THE OPERATING DIE 0R RAM IN AN EXTRUSION PRESS Siegfried Quante, Dusseldorf, Germany, assignor to Lindemann Maschinenfabrik G.m.b.H., Dusseldorf, Germany, a joint-stock company of Germany Filed May 3, 1967, Ser. No. 635,900 Claims priority, application Germany, May 13, 1966, L 53,577 Int. Cl. B21c 23/00 US. Cl. 72-263 8 Claims ABSTRACT OF THE DISCLOSURE A device for fastening and centering the operating die or ram in an extension press by means of a pair of relatively to the ram axis longitudinally converging pressure loaded clamping pistons movably mounted in a cradled open-top support for the ram; said support is attached to and moves with the hydraulic driving piston for the ram and houses in its cradle an inwardly conical centering ring which embraces a conical section of the end portion of the ram and which has on its frontal face a pair of flats inclined conformingly to the operative faces of said longitudinal converging clamping pistons for cooperation therewith.

BACKGROUND OF THE INVENTION My invention relates to a device for fastening and centering the driven die or rain in an extrusion press by hydraulic clamping pistons arranged in the ram holder.

In a known device, the ram is axially inserted into a holder and is fastened therein by hydraulically operated slides inclined on the horizontal and distributed around the circumference of the ram holder. The end faces of the slides engage radially into an annular groove in the base of the ram. To center the ram in the holder, the latter is provided with an axially movable centering ring whose conical opening cooperates with a corresponding conical face of the ram. The centering ring and conical face of the ram are provided with complementary grooves and can be mutually locked in the manner of a bayonet joint. This known device has the disadvantage that the ram must be axially introduced into the holder and that the exact guiding of the ram, whose claws must be introduced into the grooves of the centering ring, necessitates special assembly tools. In like manner, when the ram is to be taken out, it must first be pulled in axial direction out of the holder before it can be taken out of the press. Further, the centering by the slides, which are only slightly inclined relative to the horizontal, is quite defective, so that in the known device the centering ring must be pressed by special compression springs against the conical face of the ram or respectively, in the direction of the counter-bearing of the main driving piston. To insert and remove the ram however, the force of the compression springs acting on the centering ring must be overcome, and for this reason special hydraulic pressure pistons acting on the centering ring are arranged in the ram holder. Accordingly, the known device is very complicated not only generally in its design and operation but also with respect tothe hydraulic controls of the two independent pistons acting on the centering ring and on the slides.

SUMMARY OF THE INVENTION The problem underlying the invention consists in providing a fastening and centering device of simple design which permits the operating die or ram to be easily and M 3,533,264 Ice Patented Oct. 13, 1970 quickly inserted into and removed from its holder in the press without the use of special tools. According to the invention, this problem is solved by arranging in the ram holder on each side of its longitudinal center two clamping chucking pistons whose longitudinal axes converge and are inclined toward the axis of the ram, the piston faces bearing against guide tracks or flats of a centering ring resting in a horseshoe-shaped open-top opening of the ram holder.

The special advantage of the device according to my invention results from the fact that the forces exerted by the clamping or chucking pistons on the centering ring divide into two components, one of which presses the rain embraced by the centering ring against its axial counterbearing, while the other component presses the center ring with the ram against its rear counter-bearing lying in the direction of insertion. In this way an exact adjustment of the ram in relation to the central axis of the press is always insured. A further advantage of my improved device consists therein that the ram at its free end has a centric threaded bore with eyebolt and a looking pin or bolt to be inserted into the eye of the bolt. In this way the ram and the receiver can be taken out together when the ram is in the receiver and is locked thereto by said cooperating lockbolt and eyebolt. By hooking a disassembling tool into an eyelet on the receiver shell or cover the receiver and the ram can then be lifted out of the device together.

BRIEF DESCRIPTION OF DRAWING In the following, an illustrative embodiment of the in.- vention is described in detail with reference to the drawing in which is FIG. 1 a side view, partly in section, as defined by line I-I in FIG. 2, of an extrusion press provided with the fastening and centering device according to the invention;

FIG. 2, a vertical longitudinal section along line II-II in FIG. 1;

FIG. 3, a horizontal section along line III-III of FIG. 1;

FIG. 4, an enlarged partial side view of the centering ring resting in the ram holder of the extrusion press;

FIG, 5, a horizontal longitudinal section along line V-V of FIG. 4;

FIG. 6, a vertical section through the centering ring along line VI-VI of FIG. 4; and

FIG. 7, a horizontal section through a part of the press, the ram being locked in the receiver during disassembly.

DESCRIPTION OF THE SHOWN SPECIFIC EMBODIMENT In the press frame comprising a cross-head 7 and the standards 7' is a cylinder 8, which houses a driving piston 9. A cradled cross support 11 is fastened by screws 12 to a piston 9 and includes a substantially horseshoeshaped open-top opening 10 in which centering ring 13 rests which receives and holds the head portion of ram 14. The central opening of the centering ring 13 is at least partially conical dilating towards the piston 9 and the therein received head portion of the ram 14 has a cooperating conical surface. The support 11 is desirably guided by the standards 7 of the press frame. To facilitate the insertion and removal of the centering ring with the ram 14, the centering ring 13 is provided on its accessible top surface with an eyelet 15, into which a jack can be hooked. The centering ring 13 has in the border portion of its front face (FIGS. 4 and 5) upwardly converging longitudinal bearing faces 16, 17 against which bear the frontal faces of clamping pistons 18, 19 located in conforming bores in the cradled support 11, said bores longitudinally converging and being inclined toward the axis of the ram 14.

The inclined position of the clamping pistons 18, 19 effects that after insertion of the centering ring 13 with the ram 14, when the driving piston 9 is pressure-loaded, the ram 14 is pressed by the centering ring 13 against its counter-bearing face 21 of the drive piston 9 as well as against the cylindrical contact face 22 of the horseshoe-shaped opening 10 acting as radial counter-bearing. The clamping pistons 18, 19 are connected by channels 24 or by not shown pipings with a pressure source, said pipings including according to the invention a check valve between which and the clamping pistons 18, 19 a hydraulic accumulator is arranged.

After the insertion of the centering ring 13 with ram 14, the clamping pistons 18, 19 are connected by a three- Way valve with a pressure source, so that the centering ring 13 with ram 14 are pressed against the axial counter-bearing face 21 and against the radial counter-bearing face 22 thereby the ram 14 being centered. To facilitate assembly, a certain amount of play is provided between the cylindrical inner wall of the horseshoe-shaped opening 10 of the cradled support 11 and the outer surface of the centering ring 13. Moreover, the said play effects that the clamping pistons 18, 19, when the maximal retractile force of the press pulls the ram 14 back, are pressed counter to the prevailing hydraulic pressure into their cylindrical bores by an amount corresponding to the assembly clearance until the centering ring 13 rests on the axial counter-bearing face 23. The pressure medium thus displaced by the clamping pistons 18, 19 is taken up by the accumulator, thereby causing a slight increase of pressure which upon easing of the traction forces again presses the centering ring 13 with ram 14 against its counterbearing face 21, 22.

When changing rams, the space of the cylindrical bores of the clamping pistons 18, 19 is switched to outflow by a three-way valve operated manually or electrically, while the pressure medium supply from the accumulator is shut off. When a jack is hooked into the eyelet 15 on the centering ring 13, the same together with the ram 14 can in radial direction be pulled out of the horseshoe-shaped opening 10 in the support 11. The operating flats 16, 17 arranged on the centering ring 13 then push the clamping pistons 18, 19 back into their cylindrical bores, so that the horseshoe-shaped opening 10 is completely freed for the insertion of a new centering ring with ram.

Instead of the pressure medium-loaded clamping pistons 18, 19, there may be provided in the ram support 11 correspondingly inclined screw-bolts, with which a good fastening and centering can be effected; this however, has a number of disadvantages, so that generally the use of clamping pistons is to be preferred. When said screw-bolts are used the loosening or tightening of the screws is often difficult because when changing tools after prolonged operation of the press, the insertion of a new cold ram results due to heat transfer and conduction at the ram head in length variations which have to be absorbed by the fastening screws. At the next following change of a ram it is then quite diflicult to unscrew the overtensioned screws.

To permit a rapid joint removal of the receiver and ram 14 together with the centering ring 13, ram 14 is provided with an axial threaded bore 26, into which an eyebolt 27 can be screwed. By insertion of a lockbolt 28 into the ring of the eyebolt 27, the ram 14 is locked in the receiver 25.

Disassembly is then effected in that first the receiverholder 29 with the receiver 25 is moved in the direction of the ram 14 which is locked in the receiver 25 by said lockbolt 28 and eyebolt 27. After the return movement of the receiver-holder 29, there is exposed at the receiver shell 31 an eyelet into which a gripping tool 32 can be hooked for lifting the receiver 25 and the ram 14 with 4 the centering ring 13 (FIG. 7). As soon as the receiverholder 29 is completely moved back i.e. pulled off the receiver 25, the latter and ram 14 with centering ring 13 can be lifted out of the machine together.

Having shown and described one desired specific embodiment of my invention to illustrate application of the principles thereof, it will be understood that it may be otherwise embodied without departing from such princlples and from the scope of the appended claims.

I claim:

1. In an extrusion press a device for fastening and centering the operating die or ram comprising in combination a machine frame; a power cylinder with driving piston 'mounted therein; a ram operated by said piston; a supporting member for the ram attached to the outer face portion of said piston and having a substantially horseshoe-shaped cradled interior open at its top and a cylindrical bottom; a centering ring embracing the ram and adapted to be introduced into said supporting member through its open top to slidably rest upon said cylindrical bottom; the centering ring having a central conical opening dilating towards the outer face portion of the driving piston; one end of the cam contacting said outer face portion of the piston; a pair of borings in the supporting member, said borings arranged symmetrically to the longi tudinal axis of the ram and converging in slanted position towards the driving piston; a clamping piston in each of said slanted borings having a power loaded end face and an operating end face; and operating flats on the front face of the centering ring .for cooperation with the operating end face of each clamping piston the component of the force applied by the clamping pistons in a direction parallel to the axis of the ram being greater than the component perpendicular to the axis of the ram.

2. A device according to claim 1 comprising a hydraulic power piping leading towards said clamping pistons and a hydraulic accumulator within said piping.

3. A device according to claim 1 comprising a receiver shell cooperating with the ram and an eyelet thereupon for lifting the same with the ram out of the machine frame.

4. In an extrusion press, a device for fastening the ram to the driving piston, said device comprising:

(A) a frame, a power cylinder attached to the frame, and a driving piston slidably mounted in the power cylinder, said driving piston having a power loaded end face and an operating end face;

(B) a horseshoe shaped supporting member fixedly attached to the operating end face of the power piston; and

(C) dual piston means carried by the supporting memher for clamping the ram to the operating end face of the power piston the component of the force applied by the dual pistons in a direction parallel to the axis of the ram being greater than the component perpendicular to the axis of the ram.

5. In an extrusion press a device for fastening the ram to the driving piston said device comprising:

(A) a driving piston having a power loaded end face and an operating end face;

(B) a horseshoe shaped supporting member fixedly attached to the operating end face of the power piston; and

(C) dual piston means carried by the supporting member for clamping the ram to the operating end face of the power piston, wherein the pistons of the dual piston means each have a substantially planar operating end face adapted to contact a corresponding face on the ram, the component of the force applied by the dual pistons in a direction parallel to the axis of the ram being greater than the component perperpendicular to the axis of the ram.

6. In an extrusion press, a device for fastening the ram to the driving piston said device comprising:

(A) a driving piston;

- 6 (B) a ram coaxially alignable with the driving piston; References Cited (C) meansfor laterally moving the ram with respect UNITED STATES PATENTS ig gi s gggf fgfs waxlany the ram and 3,256,729 6/1966 Rowell 72-263 (D) dual piston means for clamping the ram to the 5 498304 5/1893 q 72-263 driving piston the component of the force applied FOREIGN PATENTS by the dual pistons in a direction parallel to the 949,558 9/1956 Germany axis of the ram being greater than the component 1,036,795 8/1958 Germany perpendicular to the axis of the ram. 216,865 1/1961 Austria 7. The device of claim 6 wherein the pistons of the dual 10 1 05 7 2 1954 France piston means each have a substantially planar operating end face adapted to contact a corresponding face on CHARLES W. LANHAM, Primary Examiner the ram A. L. HAVIS, As 1 tant Examiner 8. The device of claim 6 wherein the pistons of the s 5 dual piston means are arranged symmetrically to the 15 U.S. C1.X.R..

direction of lateral movement of the ram. 72-273 

